Rheostat with rectilinear slide



Dec. 21, 1.948. F. P. sTRoTHER 2,457,095

RIVIESTAT WITH REC'ILINEAR SLIDE Filed Deo. ze, 1944` 2 'sheets-sheet 1Dec. 21,1948. F. P., sTRo'rHER RHEos'i'AT WITH RECTILINEAR SLIDE 2Sheets-Sheet 2 Filed D90. 26, 1944 Patented Dec. 2l, 1948 RHEosTA'r WITHREQTIL'INAR SLIDE Fred P. Strother, Minneapolis, Minn., assig'nor toMinneapolis-Honeywell Regulator Company, Minneapolis, Minn., acorpol'ationof` Delaware Application December 26, 1944, serial No.569,693

`I`his inventionrclates to an improved gyroscope erecting and levellingapparatus and has for one of its principal objects the concurrent andselective delivery of electric energy from a common Source Ithrough -aplurality 0f parallel circuits to `operating members. ered through eachparallel circuit or leg thereof Th@ energy delivwhich adjustableresistors are positioned, to en` ergize `a like plurality of operablemembers. The adjustable resistors may be arranged to deliver energytothe operable members throughout wide ranges so that operation of themembers may be similar or may vary considerably in relation to eachother. Moreover, the apparatus is so arrangedthat energy may bedelivered to operate theV members at a high or low speed withoutaltering or changing the settings of the resistors. Additionally, theratio of` operation f the members at high vspeed is not necessarily thesame as the ratio of operation of the members at low speed.

The improved control apparatus of -this invention may be used inconjunction with various kinds of members operated in pairs or equipmentoperated by the application of forces from more than one directionwherein the force delivered to one member or from one direction maydiffer from the .force delivered to the other member or from anotherdirection. The present control apparatus is especially adapted to beused to operate the erect- Aing or levelling mechanism of gyroscopes.However, its use is by no means conned to such employment. Asillustrative of the adaptability and one `of the uses of the improvedapparatus it is herein shown and described in conjunction with themethod and means for -stabilizinggyro devices disclosed in my co-pendingapplication, Serial No. 482,217, iiled April 7, 1943, which issued asPatent No. 2,417,573 on March 18, 1947.

It is understood that any body rotating, particularly at a fairly highangular velocity, about an axis tends to resist motion of that axis inany direction other than paralled to itself. The application of a forceto the axis of the gyroscope tending to rotate it out of this positioncauses a phenomenon known as procession 0f the gyro-` scope, that is, iteifects a rotation of the axis of the gyr-oscope not in the plane ofaction of the force, but in a plane at an angle of 90 degrees with theplane of action of the force, the angle being measured in the directionof rotation of the gyroscope.

7 Claims. (Cl. 201-48) f 2 In my co-pending application, the axis ofrotation of thefgyroscope is maintained in or moved toward its positionof `orientation by the operation of electromagnetic means. Theelectromagnetic means comprises two-sets of elements positioned torotate on axes at'right angles to each other and normal to the axis ofrotation of the gyroscope. Thus, when the axis of rotation of the gyromoves from its Lplane offorientation'and from the plane of etherof theright angle axes, two forces are required to right the gyroscope. If theelectromagnetic elements rotate on equal radii then equal input in'eachelectromagnetic element will result in equalforces applied to differentsides'of the gyrosc'ope axis. However, the construction of a gyroscopehaving Aelectromagnetic elements positioned to operate on preciselyequal radii would not-'only entail'slow, high precision work, but

would valso be' vextremely costly. The present structure solves thisproblem by the arrangement of resistors in each circuit which may beselectively adjusted so that the for-ces exerted againstzthe axis of thegyroscope may be precisely equal `althol'igh there may be considerabledifference in the energy applied to and the moment ofthe electromagneticelements. Additionally, the device maybe set so that control or recoveryin one directionisy at a selectivelyvdiiferent rate than control orrecovery movement in the other direction.

`In the operationA ofj gyro stabilizing or levelling devices,`especially those used in the control and v 'operation of planes andlaviation equipment, it' is at times desirous and advantageous to makecorrection-s and alter settings lat a rapid rate and at other times tomakek the same corrections and alterations'at amuch slower rate. Forinstance, at

the beginning of a bombing run, it is essential that thebombardiercomplete the setting of the gyro on a given course and range at theearliest possible prevent overcorrection and overcontrol.

moment. Accordingly, high speed responsive mechanism is here desirableand essential. However, after the course and range have been set thehigh speed mechanism could tend to cause overcontrol and'result in theship proceeding on an erratic course. Accordingly, low speedv responsivemechanism is now desirable and essential to The improvedapparatus ofthis invention provides for both high and lowspeed operation.

Another object' of advantage and importance ofthe apparatus of thisinvention resides in the provision of means for applying a given forceto a movable member infone direction and a different forceto the samemember from -another direction.

Afstill further object of the invention is to'pro- .isan elongatedcontact member 21.

. toward low position.

vide means tending to maintain a movable member in a given position oforientation and for urging that member toward the given position atselectively different rates of speeds when the member is moved from itsoriginal position.

Additional objects of importance and advantage will become apparent asthe following detailed description progresses; reference being had tothe accompanying drawing wherein Figure 1 is a front elevational view ofan electrical unit which embodies the invention;

Figure 2 is a side elevational view thereof; Figure 3 is an elevationalview of the Ldevice shown in Figure 1 with thecover removed yandportions thereof broken away;

Figure 4 is a, vertical section taken on line 4-4 shown` in. Figure 5;

Figure'l` is similar to Figure 6 but shows the switch in high position;and

Figure 8 is a schematicwiring diagram showing the electrical circuitsandoperable positions of` the control switch.

The reference number I0 indicates generally a ,casing comprising a baseII, a back-plate I2, and

a cover I3. The parts may be secured together in any suitable manner `asfor instance by screws I4.

The cover I3 is drilled to receive a shaft I6 upon Awhich is mounted anoperating handle I1. Abutment members I8- formed on the surface of thecoverfl3 provide stops-to limit the rotational `movement of the handleI1. The handle I1 is operably movable to off, lowand high positions.

4Journaled in the plate I2, in alignment with `the shaft I6, is-a shaftI9. Formed on theinr.wardly projecting end of theshaft I9Vand rotatabletherewith isa cam 23. Peripheral portions ofthe cam 23 on opposed sidesthereof are turned .axially of the shaft.y I9 to provide operatingbosses .24. The bosses 24 arefadapted to` cooperate with lportions ofthe :shaft I6 to form a, releasable driving connection between thehandle I1Y and the `cam 23. Projecting radially from the cam 23 andspaced one from the other are two fingers 25 to .which a dat insulatingmember 26 `is secured. From the foregoing it will be apparent thatrotation of kthe handle I1 and shaft I6 rotates the shaft I9 and `cam 23together with ngers25 and the insulating member, 26 within operatinglimits dened by abutment members I8.

the ngers 25 and electrically insulated therefrom The contact member 21is adapted to rotate with the cam assembly for a purpose hereinaftermore fully `28 to maintain the cam 23 and associated parts in oi .andlow positions. Extending outwardly from the peripheral edge of the cam23 and turned .at right angles thereto to engage a biasing spring 32 isan abutment 33. Theabutment33 and biasing1spring132icooperate to loadAthecam when` it ismoved to high position and tends to urgeitAccordingly, when the handle I1 is` released while in high positionit.will

`automatically return to low position. A stop member 34 is positioned,in the path of travel Secured .to .the insulating member 26 at a pointintermediate appear. conductors 31 and 38 and slidably engaging the flatinsulating member 26 are contacts 43 and 44,

A'gagement with'contacts 46 and41.

on conducting member 6I.

,and,64 which provideelectrical connections be- .deringor in :any othersuitablemanner.

of the biasing spring 32 to prevent that member from urging the cam 23beyond low position.

Secured to the plate l2, in any suitable manner as for instance byscrews 35, is an insulating and supporting block 36. The supportingblock 38 carries a plurality of conductor blades 31, 38, 4I, and 42which are spaced and insulated one from another. Thelblades31,38,"4l,sand `Mare electrically connected to l `a. source ofsupply and resistance members as will hereinafter more fully Secured tothe free end of the blade respectively. The contacts 43 and 44 are ofconsiderable `length and are adapted to maintain the free ends oftheblade connectors 31 and 38 spaced from vthe blade connectors 4I and42, as is best shown in Figures 4 and 5. Secured to the free ends oftheblade connectors 4I and 42 are contacts 46 and 41, respectively. Contact46 extends oneach side oi blade 4I ands adapted when moved toward blade31 to engagea contact.

i aligned therewith and carried bybladet31.

From the foregoing it will be apparentthat contacts 43,V 44, 46, and-41,andpermits these members to slidably engage the insulatingmember 26.Rotation of the cam 23 in a.cloclawise direction to low position, asshown in Figure 3, causes the leaf spring 28 to engage the lowermostdwell21 and also causes the elongated-contact member 21 to engage andraisethe contacts 43 and 44 from the `insulating member. 26. `Con tinuedmovement of the cam in a clockwise directionI yto high position movesthe elongated Contact '121'` from beneath contacts 43 and'44 and `intoen- In this `position, as shown in Figure 7, blades 4I andr 42tareAmoved to the left and contact member carried by blade'4l engagescontact 48 carried'by blade 31. In this position, contact member 43` israised from the insulating member 26, butcontact 44 may slidingly engagesaid member.

Secured to the base II and extendingupward- 1y toa point' closelyadjacent the supporting .block `36 and blade connectors 31 and 38,fronrwhich `dinally therethrough and engagingl end members Secured tothe end members 51 at a point intermediate the windings' 53 and 64 andextending parallel thereto isa nonconducting member 758. Secured to theend` members 51 intermediate each winding and the non-'conducting'memberif58-are conducting `members or` snorting bars-59 and ABI. VSlidablypositionedon the'conducting member 59 and having portions thereofslidably engaging the nonconductng member '58 and the resistanceWinding'53 are Wipers 6l) and`62. Two similar Wipers G3 and 64 arelikewise mounted The wipers150,..62.63.

tween resistance winding 53 and conducting memlected positions and maythen be secured by-eol- `Theresistance Afwindingst53 and .54 A arealsoelectrieaily connected to blade connectors 38, 4|, and 42 as willhereinafter be more fully disclosed.

The improved device of this invention is illustrated in Figure 8 inconjunction with an erecting or levelling system of a gyroscope. Theschematic arrangement shown in Figure 8 is illustrative only, as thedevice may be employed in various other arrangements. The arrangement ofmercury switches 65 and 66 and course solenoids 61 and 68 and rangesolenoids 1| and 12 is similar to the arrangement shown `in myco-pending application, Serial No. 482,217, now Patent No. 2,417,573,issued March 18, 1947. In such an arrangement the mercury switch 65 ispositioned and connected to energize solenoids 61 and 68 to correctdeviation in course, and mercury switch 66 is positioned and connectedto energize solenoids 1| and 12 to correct range deviation.

Operation Operation of the improved control of this linvention is asfollows: assume for instance, that with the handle |1 in low position asshown yin Figures 1 and 8, the mercury switch 65 rotates clockwise toengage electrodes 13 and 14, a circuit is then established as follows:from a source of supply to terminal 8|), conductor 8 blade connector 31,contacts 43, 21, 44, blade connector 38, conductor 82, conductor 83,resistance 53, wiper 62, conductor 59, Wiper 60, resistance 53,conductor 85, flexible conductor 86, conductor 81. solenoid 6B,conductor 88, flexible conductor 89, electrode 14, mercury, electrode13, conductor 90 to ground. If, in the meantime, mercury switch 66 alsotilts, say clockwise, a parallel circuit is established as follows: fromconductor 82 through a portion of resistance 54, wiper 63, conductingmember 6|, wiper 64, a portion of resistor 54, conductor 92, iiexibleconductor 93, conductor 94, solenoid 12, conductor 95, electrode 18,mercury, electrode 11, and conductor 96 to ground. In the event themercury switches 65 and 66 are rotated in a counterclockwise direction,similar circuits are set up to the conductors 81 and 94. From this pointthe circuit including mercury switch 65, continues from conductor 81through solenoid 61, conductor 91, ilexible conductor 98, electrode 15,mercury, electrode 13, conductor 90 to ground. And in the case ofmercury switch 66 the circuit continues from conductor 94 throughsolenoid 1|, conductor 99, electrode 16, mercury, electrode 11,conductor 96 to ground. It is to be noted that circuits to a singlemercury switch are alternative although parallel circuits to differentswitches may be established concurrently.

Assume now that the handle |1 is rotated clockwise to high position andthat the mercury switches 65 and 66 are both rotated clockwise, aparallel circuit is established as follows: from terminal 80 throughconductor 8|, blade connector 31, contacts 48, 46, blade connector 4|,conductor |00, conductor member 6|, wiper 64, portion of resistor 54,conductor 92, flexible conductor 93, conductor 94, solenoid 12,conductor 95, electrode 18, mercury, electrode 11, conductor 96 toground. Concurrently with the establishment of the above circuit, theother leg of the parallel circuit is energized and may be traced asfollows: from contact 46, through contact 21, contact 41, bladeconnector 42, conductors and 59, wiper 60, portion of resistance 53,conductor 85, flexible conductor 86, solenoid 68, conductor 88, iiexibleconductor 89, electrode 14,'mercury, electrode 13, conductor 90 toground. It is to be noted that this leg of the parallel circuit passesthrough but a limited if any portion of the` resistor 52. In the eventmercury switches and 66 are rotated counterclockwise, the legs of theparallel circuits from the conductors 81 and 94 are altered respectivelyas follows: conductor 81 through solenoid 61, conductor 91, ilexibleconductor 98, electrode 15, mercury, electrode 13, conductor 90 toground. And from conductor 4-94 through solenoid 1|, conductor 99,electrode 16, mercury, electrode 11, conductor 96, to ground. It is tobe noted that the two circuits leading to either mercury switch 65 or 66cannot be energized simultaneously, although either circuit leadingthrough mercury switch 65 may be energized concurrently with eithercircuit leading through switch 66. In all circuits, the return isthrough ground connected to conductor |04 to thesource. It will beapparent from the foregoing that herein is provided a control forparallel circuits wherein each leg of the circuit may be controlled andadjusted independently or relative to theadjustment of the other leg.Moreover, the arrangement includes means whereby a second parallelcircuit may be controlled through portions of the same resistor elementused in controlling the rst parallel circuit. Additionally, theseparallel circuits may be adjusted relative to one another.

It will be apparent from the foregoing that the improved device of thisinvention when used in conjunction with two controlled elements may beso adjusted that the operation of one element is relative to theoperation of the other element. For instance, when the device of thisinvention is employed for controlling a gyro erectingv or levellingsystem that portion responsive to course deviation may be operated at arate altogether diil'erent from the rate of operation of the rangecontrolling'portion. Likewise, each may be operated at a high or lowrate in which the relative speed of each portion may be selectivelyaltered.

It will also be apparent to those skilled inthe art to which theimproved device of this invention appertains, that numerous changesindesign and construction may be made without departing from. the spiritor scope of the invention. Accordingly, the patent granted hereon is notto be limited to the precise embodiment or illustration here disclosedor in any other manner except as may be necessitated by the terminologyof the appended claims when givenl the range of equivalents to whichthey may be entitled. Y

I claim as my invention: 1. In a control: a resistance winding; ashorting bar; a plurality of contact members slidably mounted on saidshorting bar for making movable connection with said winding; amulti-position switch; an input connection; an output connection; meansconnecting one end of said winding to said output connection; means,including said switch in one of its positions, for connecting said inputconnection to the other end of said winding; and means, including saidswitch in another of its said positions, for connecting said inputconnection to said shorting bar.

2. In a control: a pair of resistance members; an insulating member; anda pair of conductive members; means mounting said members in spaced,generally parallel relationship substantially in a common plane so thatsaid insulating member lies between said resistance members and so thatsaid conductive members lie between said insulating member and saidresistance members; and resilient contacting members slidable along saidconductive members, each said resilresilient member in adjusted;position along,`

`sind conductive member.

k3.` In a control; a` pair of resistance members, `naniinsulatingmember, and a pair `of conductive members; means mounting said members iin Aspaced, generally parallel relationship substantially in a commonplane so that saidl insulating Vmember lies `between saidresistancevmernbers and so that said conductive members lie between saidinsulating member and said resistance memibers; resilient contactingmembers slidable` along i. said conductive members, each said resilientmembercomprising a portion for electrically connectl ing saidresistancemember and said conductive member and a portion formechanically contactringsaid insulating member to maintain said re-vatlient member in adjusted position along said conductive member; andswitchingimeanscon nected to said resistance means and said con-:ductive members for establishingr a plurality of :electrical circuitstherethrough.

4. In a control, a switch having a plurality ci Contact makingpositions, a pair of resistance windings, means short circuiting anydesired cenitral portion of each of said windings, an input lconnection, a plurality of output connections; and

V,moans connecting said switch and said windings to provide a seriescircuit between said input connection and each of said outputconnections in each position of said switch, each said series cir `cuitin aflrst position of said switchV comprising both end portions of oneof said windings, each said series circuit in a second position of saidswitch comprising one end portion only oi one of said windings.

V5. In a control. a switch having a plurality of contact makingpositions, a pair of resistance windings, a pair of slidableelectrically connected contact means for making intermediate' connec--Vtion with each of said windings, an input connection, a plurality ofoutput connections, and means connecting said switch and said windingsto provide a series circuit between said input conne@u -tion and each ofsaid output connections in each Kposition of said switch, said seriescircuits in a rst position of said switch comprising portions of saidwindings and all of said Contact means, said series circuits in a secondposition of said switch comprising portions of said windings and onecontact means only of each of said` pairs.

6.` A rheostat for controlling the energization oi Ian electrical devicecomprising an `input conductor, an output conductor, a resistancewinding, afpairlof slidable membersmaking contact with saidwinding tosubdivide it electrically into a number of portions, switch meansmovable into either of 'a pair 'of operative positions, electricalconnections through whichmovement `of said switch into one of saidportions completesa series electric circuit from said input terminalthrough said switch and `portions of said winding to saidoutput-terminal and electrical connections through which movement ofsaid switch into another of said positions completes a series circuitYfrom said input terminal through said switch and one ofsaidfportions ofsaid winding tosaid output terminal.

7. A rheostat comprising, in combination,

vswitch means including two sets of xed'contacts l windings, and saidelongated conductor respectively to the remaining contacts of said sets,so as to provide a circuit of adjustable resistance between said inputconductor and one of said output conductors in each` positionof saidmovable member of said switch means.

FRED P. STROTHER.

REFERENCES CITED The Vfollowing references are of record in the file cithis patent:

UNITED STATES PATENTS Number Name Date 4669,362 Emmett -Mar. 5, 19011,157,028 Noble Oct, 19, 1915 1,587,996 Warren June 8, 1926 2,009,380Berger \July 30, 1935 2,061,887 Wyman Nov.l 24, 1936 2,077,503 WinningApr- 20, i937 2,177,832 Knos Oct. 31, 1939 2,301,704 Kempton Nov. 10,1942 FOREIGN PATENTS Number Country Date 212,630 Switzerland Dec,15,71940 OTHER REFERENCES Forsythe, Journal Optical Soc. Am., vol. VI,June 1922, page 376.

